Field of the Invention
This invention relates in general to wear sleeves for use on circular shafts for engagement with annular seals. In particular, the invention relates to a wear sleeve for use with an annular seal used in association with an anti-friction bearing to retain liquid lubricant within the bearing.
Description of Prior Developments
Shaft surfaces are usually left relatively rough in order to minimize shaft-machining expenses. This presents a sealing problem insofar as a rough shaft surface will not seal properly against an associated annular elastomeric seal surface. Moreover, the machine marks tend to cut into the seal surface so as to shorten the seal life. To overcome these problems, smoothly-surfaced wear sleeves are often press-fit onto the shafts to provide a smooth surface in slidable engagement with an associated annular shaft seal.
Wear sleeves are shown in U.S. Pat. No. 2,818,283 to Hutterer, U.S. Pat. No. 3,207,521 to Dega, and U.S. Pat. No. 3,214,180 to Hudson, et al. In its simplest form, the wear sleeve may merely be a cylindrical tube having an axial length of about one inch and a radial wall thickness of about 0.05 inch. The tube inner diameter is about equal to or marginally smaller than the shaft diameter to permit installation of the tube or sleeve onto the shaft by a press-fit operation.
Wear sleeves are commonly formed from flat sheet material by a stamping and drawing process. Initially, annular flat metal disks are stamped from a flat sheet. Each disk is then subjected to a cold extrusion or drawing process whereby the annular disk is reformed into an annular sleeve configuration in a known fashion.
This conventional process generates a considerable amount of scrap material since the circular sections that form the holes in the annular disks are scrap. Typically, the scrap losses are as much as 60% of the raw material used. The present invention involves an economical process for making wear sleeves wherein scrap losses are/ considerably reduced. Typically, the scrap loss is about 5%.